@JedClampett, Not in the US and plus the contractor hasn't actually priced the work according to the complexity. Temporary work is always at the back of their mind when tendering. Otherwise they wouldn't get the job. I have yet to agree to proceed unless the contractor has given me free hand to...
@EireChch, Just thinking out loud. The contractor did think about using sinking method to do but their concern is that if the structure they are sinking into the ground tilts too much then it will be end game for them. So maybe using an extra sheet pile cofferdam to help as a guide? I know this...
Just as a reference, the KL twin towers in Malaysia were built on cofferdams infilled with mass concrete down to quite a significant depth. You can Google the info. It was concreted down to competent strata. I believe it's limestone which is very common in KL.
After much deliberation, I have decided to forego the cofferdam method of construction due to the poor ground condition.
I have another alternative. Would doing the sinking method using sheet pile cofferdam as a guide be a better solution?
@EireChch - I applied a FOS of 1.15 on gross passive pressures . And the contractor in a way is improving the soil on the passive side as well using driven piles to competent stratum. They will drive piles into the ground prior to setting up the cofferdam and excavating to formation level. The...
In this situation I would go with contiguous bored pile walls. Might not be as costly as you think. 15' back space is only less than 5m which is no space at all to work with.
Just to add on what I have posted above. I have since got myself Reward 2.8 from the UK to help with my cofferdam design. I read in the deepexcavation guidebook to actually have different software to analyse the same problem so I can compare the two results. Not going to argue with the expert. Lol!
Hi all,
Thanks for your input. After speaking to a local geotech expert and the software designer, I will be doing the following.
FOS 1.2 for materials
FOS 1.2 for earth pressure (active side)
FOS 1.2 for moment, shear and prop forces
I am pretty much covering all angles here when it comes...
I am DeepEX user for a few years now. Slowly building up the modules as I went along. The software is very sophisticated as mentioned above. Maybe too sophisticated. LOL. Compared with say Wallap or Reward which I have used before, Deepex has tons of inputs which can be very daunting. As with...
Hi all. I am working on a cofferdam design. Since this is a temporary structure, I am wondering if I can use FOS=1 for soil analysis as well as structural design? Thanks.
Hi HTURKAK,
Thanks for the response. I will post more info shortly but would like to just say the contour you see is the contour of top steel area in direction 1 or 2. Area of steel isn't that much different. Suffice to say the area of 1300mm2 per m run is the area of steel required for that...
Ok. I have been reading some topic on similar subject and the method of averaging the peak moment was mentioned several time. I till read through some of the resources mentioned.
Hi all,
I have a problem I would like to have better understanding of. Its a flat slab design supported on columns. I am using Protastructure to analyse the slab by FE method. The result is showing the contour of the top hogging reinforcement near the column.
Here is a snapshot of the top...
Hi Hokie66,
I have designed a spun pile which is basically inserted into a prebored hole in hard clay. Spun pile has no pile shoe hence my design by right should just take the area of the annulus of the spun pile to calculate base capacity. I would like to calculate the capacity of the base by...
Hi,
I need to calculate the capacity of a concrete plug in a spun pile to resist a push force. Tests have been conducted and written about it and published but these are actual tests to determine the shear stress at the interface by dividing the failure force kN against the surface area of the...
